Vyper up to 0.3.9 raw_call/create_from_blueprint/create_copy_of out-of-bounds write

Summaryinfo

A vulnerability identified as critical has been detected in Vyper up to 0.3.9. Affected by this vulnerability is the function raw_call/create_from_blueprint/create_copy_of. This manipulation causes out-of-bounds write. The identification of this vulnerability is CVE-2023-42443. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in Vyper up to 0.3.9 and classified as critical. Affected by this vulnerability is the function raw_call/create_from_blueprint/create_copy_of. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

Vyper is a Pythonic Smart Contract Language for the Ethereum Virtual Machine (EVM). In version 0.3.9 and prior, under certain conditions, the memory used by the builtins `raw_call`, `create_from_blueprint` and `create_copy_of` can be corrupted. For `raw_call`, the argument buffer of the call can be corrupted, leading to incorrect `calldata` in the sub-context. For `create_from_blueprint` and `create_copy_of`, the buffer for the to-be-deployed bytecode can be corrupted, leading to deploying incorrect bytecode. Each builtin has conditions that must be fulfilled for the corruption to happen. For `raw_call`, the `data` argument of the builtin must be `msg.data` and the `value` or `gas` passed to the builtin must be some complex expression that results in writing to the memory. For `create_copy_of`, the `value` or `salt` passed to the builtin must be some complex expression that results in writing to the memory. For `create_from_blueprint`, either no constructor parameters should be passed to the builtin or `raw_args` should be set to True, and the `value` or `salt` passed to the builtin must be some complex expression that results in writing to the memory. As of time of publication, no patched version exists. The issue is still being investigated, and there might be other cases where the corruption might happen. When the builtin is being called from an `internal` function `F`, the issue is not present provided that the function calling `F` wrote to memory before calling `F`. As a workaround, the complex expressions that are being passed as kwargs to the builtin should be cached in memory prior to the call to the builtin.

The weakness was shared 09/19/2023 as 3609. It is possible to read the advisory at github.com. This vulnerability is known as CVE-2023-42443 since 09/08/2023. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/19/2023).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Name

• Vyper

Version

• 0.3.0
• 0.3.1
• 0.3.2
• 0.3.3
• 0.3.4
• 0.3.5
• 0.3.6
• 0.3.7
• 0.3.8
• 0.3.9

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

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